Rotary cutting assembly

ABSTRACT

An improved cutting assembly for rotary lawn mowers, edgers, trimmers or the like, including a body member arranged for rotating about an axis normal with the cutting plane. At least two cutting lines are attached to the body member on a compound spool for rotation therewith in the cutting plane. The invention includes means for detachably securing the lines to the body member and for storing a supply of the line on the spool so that the line may be paid out as the working portions of the line become shortened through wear. The cutting lines are preferably nonmetallic so as to reduce the hazardous condition which would otherwise be present for the operator and still provide an apparatus which will cut with great efficiency and safety.

This is a continuation of application Ser. No. 706,623 filed July 19,1976, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention:

This invention relates to an improved cutting assembly in the form of atorary head for a rotary lawn mower, edger, trimmer or the like. Thepreferred embodiments are in the form of portable hand-held type lawnmowing and edging tools wherein the cutting element is safe in most usesand avoids the hazardous conditions created by prior art devices. Moreparticularly, this invention embodies an improvement over the type ofassembly generally depicted in U.S. Pat. No. 3,826,068.

2. Description of the Prior Art:

The prior art is prolix with attempts at solutions to provide a safe,efficient, and simply constructed rotary head for rotary lawn mowers,edgers, trimmer and the like. Heretofore, the rotary head, or cuttingblade, of rotary lawn mowers, edgers, and the like, have comprised arotating metal bar or the like which is rotated at sufficient speeds toeffect cutting of grass, weeds, or the like. However, such bars createhazardous conditions in that when they strike certain objects they actupon those objects in a fashion to create and project dangerous missileswhich may strike the operator or individuals in the area of work.

Various attempts have been made to overcome the aforesaid hazardousconditions created with rigid-type metal cutting blades of the priorart. Most of these attempts to overcome the problem involve theutilization of some type of flexible flail which will have sufficientresiliency so as not to propel objects which are struck at highvelocities. Most of these resilient-type cutting elements of the priorart suffer a disadvantage in that they are not safe and mere resiliencyis not sufficient to insure that the dangerous conditions will not becreated when rotation is effected at desired cutting speeds. Further,the prior art cutting elements are generally not provided with means foreasy replaceability in the event of wearing out and are usuallyexpensive to replace.

The result has been that most of the prior lawn edging apparatus havebeen unsatisfactory because of the dangerous conditions created by therotating head. As a consequence, most lawn edging and trimming aroundtrees and the like, which would otherwise be damaged by the metalblades, must be done manually, which is both laborious and timeconsuming.

There is depicted and described in U.S. Pat. No. 3,826,068, anembodiment of a rotary lawn mower, edger, trimmer or the like, having adisc-like head member arranged to be rotated by a motor, and containingfour spools housed therein in diametrically opposed relationship to theshaft of the motor. A length of flexible non-metallic line is coiledabout each of the four spools, whereby the free travelling end of eachof the four lines extends generally peripherally from its respectivespool and the head and whereby the free travelling ends of the fourlines will be swung arcuately about upon actuation of the motor to cutvegetation and the like and with the four lines each acting in thefashion of flails.

Use of the device of U.S. Pat. No. 3,826,068, has revealed that, underideal operating conditions, it will mow, cut, edge, and trim grass andother vegetation effectively. Furthermore, it possesses the significantadvantage that it is much safer to use then the more conventionalcutters, in that it does not cause stones or other solid objects to bedischarged in a dangerous manner, and it is almost completely incapableof causing any significant injury to persons or pets struck by any oneor more of the flail line members. In fact, it is a reasonable statementthat the device of U.S. Pat. No. 3,826,068, will actually cutsubstantially only the vegetation to which it is directed.

On the other hand, however, the device of U.S. Pat. No. 3,826,068, isalso subject to certain disadvantages such as to limit its practicalvalue to some degree. In the first place, it is of complex constructionand is difficult to manufacture by virtue of its four spool arrangement.This multi-spool arrangement results in a device possessing a verycomplex internal construction. In the second place, the four spoolconstruction of the device renders the device cumbersome to use andcumbersome to repair. The cumbersome construction of four spools alsoresults in unnecessary tangling of the four flail line members. Anotherdisadvantage of the device of U.S. Pat. No. 3,826,068, is that by virtueof its possessing four flail line members, breakage of any one of thelines during use of the device results in unbalancing of the head duringrotation. Thus, the fact that the device possesses four flail linesresults in more opportunity for line breakage with the result that thereis more chance for head unbalance.

These disadvantages of the prior art, and especially the aforementionedU.S. Pat. No. 3,826,068, are overcome with the present invention, and acommercially acceptable vegetation cutter and the like are providedwhich is not only fully capable of cutting vegetation under mostoperating conditions, but which is also fully capable of other tasksbeyond the capabilities of the device of U.S. Pat. No. 3,826,068. Moreparticularly, however, the embodiment of the present invention issimpler and easier to construct, possesses a less complex internalconstruction, and eliminates the cumbersome multi-spool arrangement,without sacrifice of the safety features and advantages accorded to thedevice of U.S. Pat. No. 3,826,068, and provides a more balanced head inthe event of line breakage during operation. Thus, the present inventionincludes a single spool of compound construction versus the multi-spoolsof the device of the aforesaid U.S. patent.

It is therefore a feature of this invention to provide an improvedcutting head or assembly for rotary lawn mowers, edgers, trimmers or thelike, which will provide a solution to the aforesaid problems andprovide a rotating cutting assembly which is safe for use, whicheliminates the aforesaid manual labor, and which can be operated with aminimum of skill.

SUMMARY OF THE INVENTION

This invention is for an improved cutting assembly for a rotary lawnmower, edger, trimmer or the like. It includes a body member arrangedfor rotation about an axis generally perpendicular with or normal to thecutting plane. It includes at least two nonmetallic cutting linesattached to the body member for rotation therewith in the cutting plane.The line is characterized by being constructed of a material compositionto render the line substantially flexible in the static condition.Certain embodiments of the invention includes means for detachablysecuring the lines to the body member so that the same may be replacedafter wear. Means may also be included with the body member for storingsupplies of line in the nonworking condition whereby the working lengthof the lines may be lengthened on occasion as the working length becomesshortened during use thereof. Certain embodiments of the invention mayhave line storage means supported in the body member, which storagemeans is in the form of a spool locked from rotation, but which may bereleased so that additional line may be paid out as the working lengthbecomes shortened during use due to wear.

In the ideal embodiment of the present invention, a circular head memberis provided which contains but a single spool of the compound type andbeing positioned concentrically with the axis of rotation of the motorshaft. The spool includes a pair of stacked storage compartments whicheach receive a separate cutting strand or string. Each strand extendsoutwardly of the head member in diametrically opposed relationship oneto the other. Thus, with the spool concentrically mounted, thisembodiment of the invention permits the device to perform taskscompletely beyond the device as depicted in U.S. Pat. No. 3,826,068.

It has been discovered that a cutting line acts in the nature of a fanblade. Thus, as the line is rotated a blowing effect is created. As willbe apparent, as the number of lines increase so does this blowingeffect. The blowing effect, it is noted, increases power requirements onthe motor and also reduces cutting efficiency to the extent that itcauses the vegetation, grass for example, to bend down at angles to thecutting plane resulting in an inferior cut. The two string arrangementof the present invention on the other hand minimizes the disadvantagesof the blowing effect inherent in the four string device of U.S. Pat.No. 3,826,068.

It has also been discovered that the rotational balance of the headmember is related to and effected by the number of line members of theunit acting as flails. Any imbalance is undesirable to the extent thatit is transmitted to the bearings and wear portions of the motor whichreduces the useful life of the power source. Since balance is a factor,it is preferable to have more than one line member at equally spacedpositions around the head. Four line members are not ideal because ofthe blowing effect previously mentioned. In addition, four lines createwind resistance which in turn increases power requirements on the motorwithout increasing cutting effectiveness. A two string arrangement has,therefore, been found to be ideal. This arrangement possesses theadvantages that its cutting effectiveness is better as compared tosingle string devices. The two string arrangement, further, has lesstendency for unbalance and less production of blowing than the fourstring variety.

These and other features and advantages of the present invention willbecome apparent from the following detailed description, whereinreference is made to the Figures in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing an operator operating a form of portableapparatus with which this invention is adapted for use.

FIG. 2 is a central vertical sectional view of the embodiment havingmeans for storing a supply of lines which may be paid out atpredetermined times to lengthen the working length of the cutting lines.

FIG. 3 is a side elevation view along line 3--3 of FIG. 2.

FIG. 4 is a generally cross-sectional view taken along line 4--4 of FIG.2.

FIG. 5 is a top plan view of the head or housing of FIG. 2.

FIG. 6 is an exploded view of the parts of the assembly of FIG. 2 inunattached condition.

FIG. 7 is a sectional view of the cover shown in FIG. 6.

FIG. 8 is a sectional view of the housing shown in FIG. 6.

FIGS. 9 and 10 are detailed views of the bearing element feature of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, an operator 11 is shown carrying aportable-type lawn mowing and edging device generally designated by thenumeral 12, having a power means in the form of motor 13 on therearward-end thereof and provided with a forwardly extending casing 14which supports the cutting element designated by the numeral 15 andwhich provides rotational movement thereto via a rotary drive shaftinside casing 14. By manipulation of casing 14, the cutting plane ofcutting element 15 can be arranged to be either horizontal or verticaland used to cut along sidewalks, around trees and rocks, and alongfences and the like where it is difficult or unsafe to cut withconventional devices.

Cutting lines suitable for use in accordance with the present inventionmay be composed of a variety of materials, as for example anelastoplastic extrusion which has been stretched to align the moleculesaxially. An example of such line is a nylon monofilament such as fishingline. However, other lines may be used, as for example, yarn, cord,rope, twine, braided line, or monofilament, whether described aselastoplastic, elastomeric, natural fiber, or synthetic fiber, andwhether compounded of several materials. Nevertheless, there are certainparameters within which the lines must fall in order to be effective.

It is preferable that the cutting lines be of a non-metallic materialfor reasons of safety. For instance, when metallic lines break, theytend to create projectiles during operation of the device which createhazardous operating conditions.

The cutting lines should preferably have sufficient fatigue, abrasion,and impact resistance to allow reasonable service life. Further, theline should have sufficient tensile strength to allow a reasonableservice life. The line should preferably be as lightweight as possibleso that when the line shears or breaks during use and is thrown from thecutter head, it will cause the least damage upon contact with persons orobjects.

It has been determined that a cutting line fitting within the aboveparameters will have an effective length to diameter ratio and materialcomposition which renders the line essentially flexible in a staticposition. This effective length to diameter ratio for the line willusually be greater than 20:1. It has been found that the best cuttinglines for the purposes of this invention are extruded nylon line of thetype often used as fishing line. The cutting line should have an optimumdiameter in the range of 0.062 to 0.082 inches. The maximum range ofdiameter of the cutting line has been found to be 0.035 to 0.125 inches.Thus, the cutting line should be not less than 0.035 inches in diameterand up to an effective maximum diameter which will be substantially0.125 inches.

Although the aforesaid cutting lines are essentially flexible while inthe static condition, they become rigid and taut under dynamicconditions of rotation. The normal rotating speed is on the order of3000-8000 RPM depending upon factors such as the extended length of thecutting line, the diameter of the cutting line, and the type of drivingmeans selected. During rotation of the cutting line in the dynamiccondition and at the proper speed, the cutting lines are caused tobecome sufficiently rigid whereby their tips sever vegetation underimpact therewith.

To provide optimum tip speed, the housing or head assembly is preferablyrotated about 3000-8000 RPM as hereinbefore stated, and is preferablyabout seven inches in diameter. Effective working length is the lengthfound appropriate to cut vegetation. It has been found that a workinglength of six and one-half inches is advantageous. Thus, if two linesare used, a cutting path of twenty inches is provided. Effective cuttinglength is the optimum length of the line member. The effective cuttinglength of the cutting lines is preferably in the range of three to teninches, such that the preferable total diameter of housing and cuttinglines in the dynamic condition is in the range of fourteen tothirty-four inches. It has also been found that there may be a limit onthe number of cutting lines which may be attached to any one disc. Ifthe number is too great, they tend to become tangled.

Referring now to FIGS. 2-8, the embodiment of the invention will bedescribed, which embodiment provides means for paying out the cuttinglines as the same become shortened through use.

Referring now specifically to FIGS. 2 and 3, a casing 28 is shown havingmounted therein flexible drive shaft 29. It is to be understood thatdrive shaft 29 is arranged for rotation by appropriate power means suchas those shown in FIG. 1, so that casing 28 may be turned by theoperator to change the cutting plane to horizontal, vertical, orotherwise, as required for the cutting job.

The lower end of drive shaft 29 is provided with a square end 30, whichis arranged for insertion into a coupling 31 for rotation therewith.Coupling 31 is arranged for rotation in a power head generallydesignated by the numeral 32, which is arranged for attachment to thelower end of casing 28 as shown. These attaching means take the form oftwo oppositely spaced apart lobes 33 having screw holes therethrough andin which are mounted a pair of clamping screws 35. In addition, powerhead 32 is provided with a longitudinal slot 34 intermediate each oflobes 33 such that, upon tightening of clamping screws 35, power head 32is frictionally attached to casing 28.

The lower end of power head 32 is provided with an enlarged flange 37thereabout and with a central aperture therethrough in which is pressmounted a pair of bushings 38 and 39.

The lower end of coupling 31 is arranged for threading engagement withdrive shaft 40 which extends downwardly therefrom and is spaced from thelower end of coupling 31 by thrust washer 41. Shaft 40 extendsdownwardly through bushings 38 and 39 and is provided with an enlargedportion 42 which acts as a thrust bearing against lower bushing 39.Portion 42 has threadedly attached to the lower end thereof an insertmember 43 with a lower extending portion 44 which extends downwardlytherefrom and is arranged for threading engagement with attachmentinsert 47 in the rotary body generally designated by the numeral 48.Body 48 may be of plastic or metal and is arranged for rotation by shaft40 and is provided with cutting lines, which are to be describedhereinafter.

Rotary body or housing 48 is provided with a top wall member 49 and aside wall member 50 extending down about the sides thereof a substantialdistance. Rotary body 48 is arranged for demounting from casing 28 byloosening clamping screws 35, which permits removal of power head 32from casing 28 and separation of drive shaft 29 from coupling 31.Thereafter, shaft 40 can be removed from coupling 31 and power head 32and, subsequently, unthreaded from rotary body 48, which permits removalof housing 48 and access to the interior thereof.

Housing 48 is provided with means for storing a supply of cutting linestherein, which cutting lines are arranged for paying out atpredetermined times to vary the effective working lengths of the cuttinglines.

Accordingly, housing 48 is provided with a single spool compartment 51which is located within rotary housing 48 as shown in FIG. 4. The spoolcompartment 51 is provided with line exit channels 52 and 53 leadingoutwardly to the periphery of rotary housing 48 as shown. The outwardends of exit channels 52 and 53 are curved or otherwise streamlined soas to provide a minimum of stress on the cutting lines which areextended radially outwardly thereof.

The upper side of cover member 54 is provided with a recess 55circumferentially thereabout which is arranged for mating with lowerflange 56 of wall 50 as shown in FIG. 2. Thus, by tightening attachmentmeans 47, cover member is drawn into mating engagement with wall member50 of housing 48.

Within spool compartment 51 is located spool member 57 which comprises afirst annular wall 58 having three flange elements 59, 60 and 61extending radially outwardly therefrom. These flange elements definetogether with wall 58 a pair of storage compartments indicated at 62 and63. Spool 57 is arranged for insertion into rotating housing 48 whencover member 54 is removed. In operation of the device, spool 57 rotatesalong with housing 48, except upon lengthening of the lines as will bedescribed hereinafter.

The spool 57 has wound thereon a supply of cutting line of the aforesaidtype. The first supply of cutting line is received in storagecompartment 62, with the inward end 64 projecting through an opening inwall 58 which one end of the cutting line 65 may be threaded and knottedas shown on the left side of FIG. 2. The second supply of cutting lineis received in compartment 63 with the inward end 66 projecting througha second opening in wall 58 which end of the cutting line 67 maylikewise be threaded and knotted as shown. As an alternative, the ends64 and 66 may be embedded in wall 58 of spool 57 in cases where thespool will be replaced by a prewound replacement spool. There is thusprovided a supply of cutting line in each of storage compartments 62 and63. The opposite end of each cutting line is arranged for paying outthrough a respective line exit channel 52 and 53 as shown in FIG. 4.Thus, line 65 pays out peripheral aperture 52 while line 67 pays outperipheral aperture 53.

In order to adjust the working length of lines 65 and 67, reference ishad to FIG. 4 wherein there is shown an annular locking ring 68 disposedbetween wall 58 of spool 57 and portion 69 of housing 48. The ring 68 isnormally in abutting relationship to wall 49 as in FIG. 2, but ismovable downwardly towards cover member 54, such movement being guidedby wall 58 and portion 69 of housing 48. Ring 68 includes an outwardlyprojecting tab member 70 for engagement and disengagement withcorresponding stop members of spool 57 to be described hereinafter.

Referring to FIG. 2, there will be seen a spring biasing elementdesignated by numeral 71 and disposed at one end against cover member 54and at its other end against locking ring 68. Spring 71 biases lockingring 68 against wall member 49 of housing 48 and maintains the ring inthis abutting relationship during rotation of housing 48 duringvegetation cutting operations.

Located exteriorily of housing 48 as seen in FIG. 5, is a release member72 having a pin element 73 attached thereto. The pin element 73 is inturn attached to locking ring 68 via a suitable opening 74 extendingthrough wall 49 of housing 48. The release member is adapted to be moveddownwardly toward wall 49 by the application of manual pressure beingapplied thereto. Such movement of release member 72 forces the pin 73downwardly through opening 74. This action in turn, forces locking ringdownwardly towards cover member 54 against the biasing resistance ofspring element 71. Upon release of manual pressure applied againstmember 72, spring element 71 forces locking ring 68 upwardly againstwall 49 which in turn, through its connection to pin 73 returns releasemember 72 to its original position.

With reference again to FIG. 4, spool member 57 will be seen to includealong its inner periphery a plurality of step members indicated bynumerals 75, 76, 77, and 78. Each stop member is seen to comprise anindent in the inner periphery of spool 57. These indent or stop membersare formed in an inwardly extending flange 79 of spool member 57, thisflange 79 being located at the upper end of the spool as seen in FIG. 2.

As illustrated in FIG. 4, tab 70 is seen to be engaged by stop member78. This engagement between elements 70 and 78 lock the spool 57 withinhousing 48 whereby spool 57 rotates along with housing 48 during thevegetation cutting operation. Upon shortening of line members 65 and 67due to wear, it is necessary to lengthen the line members by drawingadditional line from storage compartments 62 and 63. To achieve thisline lengthening, motor 13 is stopped which in turn ceases rotation ofhousing 48 and its associated assembly. Manual pressure is then appliedto release member 72. This forces pin 73 downwardly which in turn moveslocking ring 68 towards cover member 54 against the bias of spring 71.Such downward movement of locking ring 68 frees the engagement of tab 70with stop member 78. This freeing of engagement between elements 70 and78 releases spool element 57 for rotational movement within housing 48.Thus, with the release member 72 held down, the exteriorly extendingportions of lines 65 and 67 may be grasped and pulled outwardly ofhousing wall 50. This pulling of the lines causes spool 57 in housing 48to pay out more line length as it rotates within the housing. The lineis pulled until a sufficient length extends exteriorily of the housingat which time flange 79 will have rotated to one of the other stoppositions 75, 76, or 77, depending upon how much line is removed. Uponrelease of pressure upon element 72, the spring forces locking ring backagainst the wall 49 of housing 48 and this return movement of lockingring 68 again engages the tab 70 with one of the other stop members 75,76 or 77. Upon reengagement of the tab 70 with one of the stop members,the spool 57 is again locked for rotation with housing 48 rather thanwith respect thereto. It should therefore be apparent that the upwardposition of locking ring 68 against housing wall 49 locks spool 57 forrotation with housing 48, whereby the depressed lower position oflocking ring 68 frees spool 57 for rotation within housing 48 for thepurpose of paying out additional line.

In FIG. 6, is shown an exploded view of the assembly above-referred towith identical parts in FIG. 6 corresponding to parts referred to abovewith respect to FIGS. 2-5. FIG. 7 similarly shows cover member 54 inmore detail for a better understanding of its shape and construction. Ina similar manner, the housing or head assembly 48 is shown on a largerscale in FIG. 8, identical parts and numerals corresponding to FIGS. 2-5above.

Referring again to FIGS. 5, 6 and 8, top wall member 49 of the housing48 will be seen to include a plurality of upstanding and radiallyextending fins 80, only one being numbered, extending from portion 69 ofthe housing and terminating short of peripheral wall 50. Inclusion ofthese fin members with upper wall member 49 serves to strengthen theoverall construction of housing 48 and to provide a degree of rigiditythereto, in order to withstand rugged treatment of the assembly duringuse.

In FIGS. 9 and 10, is shown a further feature of the disclosed rotarycutting assembly wherein each peripheral aperture 52 and 53 is linedwith a metallic bearin member denoted generally by the numeral 81. Thedisposition of the metallic bearing element in each peripheral apertureof housing wall 50 may also be seen in FIG. 4. As shown in FIGS. 4, 9and 10, the bearing element 81, is essentially saddle-shaped inconfiguration and follows generally the contour of the curvilinearportions of wall 50 which define each peripheral aperture. The bearingelement is preferably constructed of brass metal although other metallicmaterials are useful. The bearing element 81 is press-fitted into theaperture and will remain in place therein and in abutting relationshipto the curvilinear wall sections defining the aperture. The details ofthis metallic bearing element, its function, design, and operation, areset forth more fully in copending U.S. application Ser. No. 633,456,filed Nov. 19, 1975, now U.S. Pat. No. 4,035,912. It should be notedherein, however, that the metallic bearing elements 81 lodged withineach of the peripheral apertures of wall member 50 function to reducethe breakage rate of the cutting line members 65 and 67 by reducingfriction and heat generated between the points of contact of the linemembers with portions of the rotatable housing 48. It has beendetermined through usage of the present invention that, wherevermetal-to-plastic contact can be established at such points of frictionalengagement, reduction or dissipation of generated heat is sufficient toeliminate melting or softening of the cutting lines, thereby keepingline breakage to a minimum.

In operation, the apparatus is assembled with cutting lines 65 and 67extending generally radially outwardly therefrom to the desired lengths.Thereafter, rotary body 48 is rotated by rotation of shaft 29 to thedesired rotational speed. As a result, lines 65 and 67 will be extendedradially outwardly. from body 48 to the cutting plane, where cutting,lawn edging, or the like may be effected. As lines 65 and 67 becomeshortened through use, they can thereafter be lengthened by terminatingrotation of rotary body 48, pressing downwardly on release 72, andpulling on lines 65 and 67 to extend them to the desired distance.Thereafter, pressure is relieved on release 72 and spring 71 urges ring68 back to the lock position, at which point cutting operations can becontinued.

It will thus be apparent that this invention provides the art with anapparatus which can quickly, easily, and efficiently cut grass, weeds,and the like; over, under, around, and between trees, posts, bushes,buildings, and other stationary objects, or the like. Further, thisapparatus will be particularly safe for the operator in that thehazardous conditions prevalent in prior art apparatus have beenessentially eliminated. By making the apparatus available in a portableembodiment, the cutting plane can be effected in any direction so as toaccommodate both cutting and trimming operations as heretoforedescribed, thereby eliminating the need for manual labor in certaindifficult cutting operations.

The apparatus of this invention can be used successfully in yardtrimming and cleaning operations where there is considerable debris,such as bottles, cans, paper, wood, wire and the like, without creatinga dangerous condition in that the cutting elements of this device do notcreate missiles of such trash. Because of the nature of the cuttingelement of this invention, such objects are not thrown, but rather thecutting element acts in a resilient fashion in such a manner as not toimpart sufficient force to such articles to become missiles; or if theyare thrown, it is at a very low velocity relative to prior state of theart machines. Experience has shown that in operating an apparatus ofthis device with lines of the type described, the cutting lines mayaccidentally come in contact with the operator's shoes, articles ofclothing, or the like, without serious injury as would be the case withprior art devices. Further, in the event a portion of the cutting lineis thrown from the apparatus, such thrown portions possess low mass andlow kinetic energy and, therefore, quickly lose velocity and energy,thus rendering the same virtually harmless.

Further modifications and alternative embodiments of the apparatus ofthis invention will be apparent to those skilled in the art in view ofthis description. Accordingly, this description is to be construed asillustrative only and is for the purpose of teaching those skilled inthe art the manner of carrying out the invention. It is to be understoodthat the form of the invention herewith shown and described is to betaken as the presently preferred embodiment. Various changes may be madein the shape, size and arrangement of parts. For example, equivalentelements or materials may be substituted for those illustrated anddescribed herein, parts may be reversed, and certain features of theinvention may be utilized independently of the use of other features,all as would be apparent to one skilled in the art after having thebenefit of this description of the invention.

What is claimed is:
 1. As a subcombination,a spool-like member having ahollow core portion with at least three spaced apart external flangeportions extending radially outwardly from the outer periphery of saidcore portion; said core portion being open internally at one end thereofand with one of said external flanges being integrally joined to saidcore portion at said one end and terminating at the inner periphery ofsaid one end of said core portion and at the other end having aninternal flange integral with another of said external flanges andextending inwardly of the inner periphery of said core portion towardsthe axis of said core portion but in annular spaced relationshipthereto; said internal flange having a plurality of uniformly shaped anduniformly angularly spaced-apart recesses therein for sequentiallyaccomodating a key member; and a pair of flexible non-metallic linemembers each being wound about the outer periphery of said core portionbetween respective pairs of said external flanges.